Abstract: Waterborne coating compositions are provided comprising a polymeric film-forming resin, a non-gelled copolymer and up to about 2.1 percent by weight silica, based on the total weight of resin solids in the coating compositions. The non-gelled copolymer is prepared from about 75 to about 95 percent by weight of an ethylenically unsaturated monomer such as methyl methacrylate, butyl acrylate, butyl methacrylate, styrene, and mixtures thereof; about 2 to about 12 percent by weight of an ethylenically unsaturated monomer having one acid functional group; and about 2 to about 20 percent by weight of an ethylenically unsaturated oligomeric monomer hating a number average molecular weight of about 1500 to about 4000 and which is derived from a hydroxyl functional acid having a predominantly hydrocarbon chain of from about 10 to 19 carbon atoms. Note that the percentages by weight are based upon the total solid weight of reactants used to prepare the copolymer.

Abstract: A coating composition comprising a dispersion of an epoxy resin, a nitrogen resin crosslinker such as a melamine formaldehyde, a particulate fluorocarbon such as PTFE, and citric acid can be applied to substrates such as polysulfones and cured at low temperatures on the order of 107.degree. C. The resulting coating is especially useful as a barrier to seal the surface of the substrate and to improve abrasion resistance.